Why should you care? Because last year InformationWeek reported that simple passwords created using short, simple key sequences can be easily cracked:

"For example, a lowly P3 PC running a widely available cracking tool at just 500 MHz was able to guess the password "ChEcK12" in only 26 seconds; and today's top-of-the-line PCs could perform the same crack almost instantly. (For more examples of just how quickly simple password techniques like this can be bypassed, see this page from McMaster University). It's scary stuff."